Tuberculosis (TB) remains an important infectious disease worldwide. Taiwan is still an edemic area. In 2008, there is an incidence of 62 persons having TB per 100,000 population. To control TB, we should prevent further TB transmission via early diagnosis and treatment of latent TB. In screening the risk population for TB, patients with renal failure acquiring long-term dialysis, in addition to close contacts, have higher incidence and mortality than general population. Moreover, the risk for active TB in dialysis patients is ten to 25 times larger. In Taiwan, the dialysis group is important because it has higher prevalence (2228 per in per million people by 2009 annual report of United States Renal Data System) than other countries in the world. In particular, the dialysis patients usually has an extrapulmonary presentation for their TB, so diagnosis is always delay. Hence, we should detect latent TB in those dialysis patients for monitor them from active tuberculosis.